Wire-stretcher



' D. J. OCONNOR, C. A. NELSON AND C. NAHABED.

WIRE STRETCHER. APPLICATION FILED DEC.24 1920.

1,400,093. Patented Dec. 13, 1921.

2 SH EETSSHEET l.

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42 1 51400441 01 3 6M6 it I @5 m, awomwg D. J. OCONNOR, C. A. NELSON AND C. NAHABED. WIRE STRETCHER.

APPLICATION FILED DEC. 24. 1 920- V Patented Dec. 13, 1921.

2 SHEET SSHEET 2.

awowbo'oS warren srarss DANIEL J. OCONNOR, CHARLES A.

NELSON, AND CARL NAHABED, OF NEW YORK, N. Y.,

earner orrics.

ASSIGNORS T0 TWISTED VJIRE & STEEL 00., A CORPORATION OF NEW YORK.

WIRE-STRETCHER.

L lOtLOQS.

Specification of Letters Eatent.

retell-retina. is, 1921.

Application filed December 24, 1920. Serial No. 432,990.

tension so that they may be securely fastened and thereby hold firmly the box, or other package or receptacle together during transportation.

The object of our invention is to simplify the construction of such stretchers, and to provide a stretcher of strong, durable and effective character.

Qnc form of our invention is shown in the accompanying drawings in which Figure 1, is aside elevation.

Fig. 2, is a top plan.

Fig. 3, is alongitudinal section looking in the direction of the arrows 3, 3, of Fig. 1.

Fig. 4., is a similar view showing the pawls engaging the rack.

Fig. 5, is a cross section on line 55, of Fig. 1.

Fig. 6, is a cross section on line 66, of Fig. 1.

Same letters indicate similar parts in the different figures.

In the form shown, A and B are two independent gripping carriagesand a rack-plate C is secured at one end to carriage A and adapted to be drawn through carriage B by multiple pawl D, E, as required by moving thehandle F. The result of this action is to cause the two carriages to approach each other and tighten the flat or round wire gripped by the1n,that carriage moving which is under the lesser tension and the other carriage remaining practically stationary. That is to say :the rack-plate G and its attached carriage A will be drawn toward the carriage B if the tension of carriage B is greater thanthat of carriage A, or the carriage B will be fed along the rackplate C toward carriage A, if the tension,

A. Each of the two carriages A, B, has a smooth bottom, preferably, adapted to rest on the box or other article to be strapped, and to slide thereon readily.

Projecting laterally from each carriage is a holding plate a, 'b, respectively upon which the wire or band to be stretched is placed and where it is gripped by a suitable gripping device. This device, as shown, is in the form of a cam-lever F, F, pivoted to the carriage, at 7', 7', but it is to be understood that various other ways of gripping the wire or band may be employed if preferred, our invention relating more par ticularly to the manipulation of the rackplate which tightens the strain put upon the band or wire by the devices 'which hold the same to. the respective carriages. For the sake of clearness carriage A may be called the rack-carriage, and carriage B, the pawl-carriage, thus expressing their individual functions. r

We are aware that wire-stretchers exist in which the tightening is brought about by the use of two gripping carriages and a sliding rack but never, so far as we are aware by such a simple, strong and efficient drawing mechanism as our multiple pawl device with which carriage B is equipped. By this device many of the elements heretofore employed, such as pinions meshing with the rack, springs, ratchet-wheels, etc., are dispensed with the engagement of the multiple pawl being direct with the teeth of the rack-plate itself. And this multiple pawl arrangement is operated by a single handle Gr.

To accommodate the multiple pawl arrangement and allow a perfect freedom of action, the pawl-carriage B, is provided with a forward block H, through which the rackplate passes as through the carriage itself and which is integral with or securely attached to the carriage B by the bridge I, as by screws 0, c, (Fig. 2).

The handle G is pivoted, as at d, to the bridge I, and the short arm is curved as shown to secure freedom of swing in a comparatively small space. To this handle are of these holding pawls is limited by the stop [71,, in the block H.

The operation of our improved stretcher will, we think, be readily undersood by those skilled in such matters and is briefly as follows Vhile the device is in its inoperative position as shown in Fig. 3, the free ends of a wire or box-strap which has been placed around the box or other article to be strapped, are inserted under the cam levers F, F, on their respective holding plates a, Z). The handle G' is then thrown toward the position shown in Fig. A. This causes .one of the driving pawls to displace its holding pawl from the position shown in Fig. 3 into that shown in Fig. at, where it is prepared to hold the rack against any back-pull of the stretching wire or band. By its continued movement the driving pawl has drawn the rack-plate the distance corresponding to the number of teeth which represents the swing to which said pawl was mijnsted and hold fast as shown in said Fig. i, until the strain is relieved by the companion driving pawl going through the same set of motions. Once released, the first driving pawl is raised. to the position of Fig. 8. while the other pawl holds the rack till released in turn. It will thus be seen that the two sets of pawls, one driving and one holding, work alternately until by their successive action the stretching has been brought to the desired tension. The strap-ends are then secured by any desired method of sealing and the stretcher assumes a position which permits the free sliding of the rack-plate to its original position for another tightening operation.

lVe claim:

1. A wire-stretcher which is provided with a multiple pawl arrangement which consists of a pair of driving pawls adaoted to operate alternately and a pair of holding pawls each of which is adapted to be operated by its corresponding driving pawl during the tightening operation.

2. In a wire-stretcher a multiple pawl ar rangement which comprises a pair of driving pawls acting alternately in engaging a rack-plate, apair of holding pawls operated successively by their respective driving pawls, and a rack adapted to be moved and held alternately by each set of driving and holding pawls.

DANIEL J. OOONNOR. CHARLES A. NELSON. CARL NAHABED.

Witnesses:

ROY F. SEGAN, CLAUDE V. SUITS. 

